Only a month from now, the first All Black squad chosen by Steve Hansen, Ian Foster and Grant Fox will be revealed.

They have been trawling the expanded Super 15 series for those who retain international pedigree, new men who promise they have it and others who suggest they are worth an investment.

As the season has developed, the list of those marked with test miles still on the clock may be dwindling.

You don't have to think much outside the forlorn cast of Blues players to find the white-knuckle questions for the selectors.

They have to abandon their historic allegiances, separate their loyalty from reality and ask whether some of those who delivered the Webb Ellis Cup still have test years in them.

In doing that they have to measure their knowledge of those players and the quality of challengers for their positions.

Ma'a Nonu and Piri Weepu are prime examples in the Blues.

Sonny Bill Williams has shown repeated form at second five-eighths. His understudy would be Nonu, because of his All Black history and the lack of sting from other solid, but less dynamic, midfielders.

Weepu is in much deeper schtum. He has little form, well-documented fitness issues and a stack of other halfbacks who are in strong nick.

Andrew Ellis, Aaron Smith, T J Perenara, Tawera Kerr-Barlow, Alby Mathewson and perhaps Jimmy Cowan in that order, have shown much more consistent class. That's a list without Brendon Leonard who is still on the injured roster.

Seven players who claimed World Cup honours will be missing from the May 13 announcement of an anticipated 30-strong squad.

Half the Super 15 round robin games are almost dusted and Blues forwards Ali Williams, Anthony Boric and Keven Mealamu are battling.

Boric has a neck problem which has eliminated him while recurring calf problems have not helped Mealamu's cause. Williams started the first six games but was benched for the latest loss to the Sharks because his impact was marginal.

How does that Blues forward trio measure up against challenging faces?

Mealamu has World Cup mates Andrew Hore and Corey Flynn playing well while Dane Coles is on the rise at hooker and Hika Elliot is threatening once more.

Locks have not been a plentiful All Black resource and with Thorn departing much would have been expected of Williams, Boric and Sam Whitelock.

Jarrad Hoeata is just into action for the Highlanders, while another former All Black Jason Eaton has shown signs of a revival and Tom Donnelly is starting to front up alongside Whitelock.

Athletic menace has come from rookie Brodie Retallick while some necessary grunt is being supplied by others like Josh Bekhuis, Craig Clarke and Luke Romano.

Who else might be getting a little twitchy about being back in black? Not many. Perhaps a couple of wings because of the competition.

Wing Zac Guildford was late back into action after a suspension while Hosea Gear has brought mixed form.

They will need to sharpen because Rudi Wulf, Lelia Masaga and Ben Smith have all been All Blacks and are playing strongly.

Andre Taylor could switch roles while Sean Maitland, Julian Savea and Tim Nanai-Williams are also pushing their novel range of talents.